Boron tribromide → 3-[7-(Bromomethyl)-2-benzoxazolyl]phenol

HRID 1393348Notes

Reaction equation

HRID 1393348 reaction equation
B(Br)(Br)[Br:2].C[O:6][C:7]1[CH:8]=[C:9]([C:13]2[O:14][C:15]3[C:21]([CH2:22]O)=[CH:20][CH:19]=[CH:18][C:16]=3[N:17]=2)[CH:10]=[CH:11][CH:12]=1>C(Cl)Cl>[Br:2][CH2:22][C:21]1[C:15]2[O:14][C:13]([C:9]3[CH:10]=[CH:11][CH:12]=[C:7]([OH:6])[CH:8]=3)=[N:17][C:16]=2[CH:18]=[CH:19][CH:20]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 23033873HCID 23033873, compound

Product 1

HCID 230338983-[7-(Bromomethyl)-2-benzoxazolyl]phenolYield 98%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of boron tribromide in methylene chloride (1.0 M; 7 ml, 7 mmol) was added dropwise to a suspension of [2-(3-methoxyphenyl)-benzoxazol-7-yl]methanol (457 mg, 1.79 mmol) in methylene chloride (10 ml) at −78° C., and the mixture was stirred at the same temperature for 1 hr. After the removal of the cooling bath, the mixture was stirred at room temperature for 2.5 hrs. The reaction mixture was poured into ice-water (50 ml), and the organic layer was separated. The aqueous layer was extracted with ethyl acetate. The organic layers were combined and dried, and the solvent was distilled off under reduced pressure. The residue was purified by flash column chromatography on silica gel (n-hexane/ethyl acetate=3−1) to give 7-bromomethyl-2-(3-hydroxyphenyl)-benzoxazole (535 mg, 98%) as a brown solid.

Workup

  1. customAfter the removal of the cooling bath
  2. stirringthe mixture was stirred at room temperature for 2.5 hrs
  3. additionThe reaction mixture was poured into ice-water (50 ml)
  4. customthe organic layer was separated
  5. extractionThe aqueous layer was extracted with ethyl acetate
  6. customdried
  7. distillationthe solvent was distilled off under reduced pressure
  8. customThe residue was purified by flash column chromatography on silica gel (n-hexane/ethyl acetate=3−1)

Sources & evidence

ORD record
ord-e3fecb67be9a4d7dbf6ba78f2ba152fe
Source dataset
uspto-grants-2008_03
Patent number
US07345068B2

Reaction notes

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